/*
 *
 *  * Copyright 2016 http://www.hswebframework.org
 *  *
 *  * Licensed under the Apache License, Version 2.0 (the "License");
 *  * you may not use this file except in compliance with the License.
 *  * You may obtain a copy of the License at
 *  *
 *  *     http://www.apache.org/licenses/LICENSE-2.0
 *  *
 *  * Unless required by applicable law or agreed to in writing, software
 *  * distributed under the License is distributed on an "AS IS" BASIS,
 *  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  * See the License for the specific language governing permissions and
 *  * limitations under the License.
 *
 */

package org.hswebframework.web.dao.datasource;


import org.hswebframework.web.ThreadLocalUtils;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;

/**
 * 动态数据源接口,此接口实现多数据源的动态切换
 *
 * @see DataSourceHolder
 */
public interface DynamicDataSource extends DataSource {
    String DATA_SOURCE_FLAG = "data-source-id";

    String DATA_SOURCE_FLAG_LAST = "data-source-id-last";

    /**
     * 使用上一次调用的数据源
     */
    static void useLast() {
        use(ThreadLocalUtils.get(DATA_SOURCE_FLAG_LAST));
    }

    /**
     * 选中参数(数据源ID)对应的数据源,如果数据源不存在,将使用默认数据源
     *
     * @param dataSourceId 数据源ID
     */
    static void use(String dataSourceId) {
        ThreadLocalUtils.put(DATA_SOURCE_FLAG, dataSourceId);
    }

    /**
     * 获取当前使用的数据源ID,如果不存在则返回null
     *
     * @return 数据源ID
     */
    static String getActiveDataSourceId() {
        return ThreadLocalUtils.get(DATA_SOURCE_FLAG);
    }

    /**
     * 切换为默认数据源,并指定是否记住上一次选中的数据源
     *
     * @param rememberLast 是否记住上一次选中的数据源
     */
    static void useDefault(boolean rememberLast) {
        if (rememberLast && null != getActiveDataSourceId())
            ThreadLocalUtils.put(DATA_SOURCE_FLAG_LAST, getActiveDataSourceId());
        ThreadLocalUtils.remove(DATA_SOURCE_FLAG);
    }

    /**
     * 切换为默认数据源并记住上一次使用的数据源
     */
    static void useDefault() {
        useDefault(true);
    }

    /**
     * @return 当前激活的数据源
     */
    DataSource getActiveDataSource();

    /**
     * 获取当前激活数据源的数据库类型
     *
     * @return 数据库类型
     * @see DatabaseType
     */
    DatabaseType getActiveDataBaseType();

}
